Oligosaccharides are important in a wide variety of intracellular recognition events, including processes that mediate inflammation, cancer metastasis, and bacterial and viral infection. Glycosylation mediates the function and stability of glycoproteins, including biopharmaceuticals such as erythropoietin. (Varki, A. et al. 1999; Ernst, B. et al. 2000; Bertozzi, C. et al. 2001; Schofield, L. et al. 2002). Oligosaccharide biosynthesis is non-template directed, and leads to heterogenous mixtures of related structures that are difficult to separate. Thus, natural sources of oligosaccharides are not structurally defined, and detailed mechanistic studies of oligosaccharide-mediated events require synthetic material.